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Recording-2025-02-24T00_42_23.193Z

Inheritance Patterns

Mendelian Inheritance

  • Parents' genotypes determine offspring's traits.

  • Traits can be red or white based on genotype.

Complex Inheritance

  • Real-life examples demonstrate deviations from simple Mendelian inheritance.

  • Example: Crossing a red cow with a white bull results in roan offspring, showcasing both colors, a pattern known as codominance.

Codominance vs Incomplete Dominance

  • Codominance: Both parental traits are fully expressed (e.g., red and white coat).

  • Example: Roan cow or bull expresses both red and white colors.

  • Incomplete Dominance: A blend of traits creates a new intermediate phenotype (e.g., crossing black and white cats results in gray cats).

  • Example: Red and white Camellias produce pink flowers.

  • Important to distinguish between codominance and incomplete dominance:

    • Codominance = both traits visible.

    • Incomplete dominance = mixed phenotype.

Activity Instructions

  • Students instructed to use devices for Gizmo simulation.

  • Complete worksheet prior to starting with Gizmo.

  • Remember to visualize colors accurately (black = red in diagrams).

Discussion Points

  • Students engaged in discussing possible offspring outcomes based on different genotypes.

  • Questions on predicting mixtures of traits, encouraging analytical thinking.

Key Genetic Concepts

Alleles and Genotypes

  • Definition: Alleles are different versions of a gene.

  • Example: FW (white) and FR (red) are alleles of the feather color gene.

Phenotypes

  • Definition: An organism's observable characteristics.

  • Offspring's phenotypes described as colorful based on mixed parent traits.

Experiment Results

  • Results indicate combinations of genotypes: F r F w and F w F w observed in chicken breeding experiments.

  • Offspring from combinations of traits do not produce homozygous red chickens due to presence of a white chicken parent.

Difference in Inheritance Patterns

  • Inheritance patterns differ in expression of alleles:

    • In dominant/recessive traits, the dominant allele overshadows the recessive one.

    • In codominance, both alleles express simultaneously without one overshadowing the other.

Homework Assignments

  • Complete pages three and work on unit three project, "Journey of a Photon."

  • Emphasis on project completion and submission guidelines.

  • Reminders about quality and integrity of work submitted.